Steam-boiler.



E. MASLIN.

STEAM BOILER.

APPLICATION FILED JAN. 28, 1911 hlwn M r Patented Nov. 28, 11911.

smut. menu, or LESTAQUE, FRANCE.

STEAM-BOILER.

Specification of Letters Patent. Patented NOV. 28, 1911.

Application filed January 28, 1911. Serial No. 605,253.

To all whom it may concern:

Be 1t known that l, EMILE MASLIN a citizen of the French Republic, residing at LEstaque,Banlieue de Marseille, France, have invented certain new and useful Improvements in Steam-Boilers, of which the fol.- lowing is a specification.

One of the best means for obtaining an absolute combustion of the smoke consists in using a down-draft'furnace in which the air for combustion traverses the fuel from above. With downdraft-furnaces it is however impossible to use the ordinary grates as they would melt immediately. It has been proposed to burn the fuel upon a refractory sole but the fire-proof material is very rapidly destroyed owing to the corrosive action of the molten ashes. There is no grate known at present which is adapted to be used with downdraft-furnaces. It has further been proposed to use for downdraft furnaces agrate of infusible material composed of metal tubes in which circulates water and which is in direct communication with a steam generator. This plant is very expetnsive owing to the great difficulties connected with the execution of the same; it further is continually exposed to the danger of explosion for the reason of the intense vaporization produced in the tubes of the grate and of the rapid formation of scales in said tubes.

The present invention has for its purpose to avoid the aforementioned inconveniences, namely the high cost of construction and the danger of explosion. According to this invention the grates consist of metal tubes forming parts of one or of several thermiosiphons which are independent of each other. In each of the siphons circulates a liquid, always the same, designed to transmit the heat from the grate to a boiler, the grates being cooled by the circulation of the liquid and the liquid being cooled in the boiler. The liquid circulating in the siphon can either. be mercury, a suitable oil, a saline solution or simply water. This device is very economical and avoids an danger of explosion. If any of the tu es should burst, only the liquid contained in the corresponding siphon would drop into the furnace without any danger of explosion as the quantity of liquid contained in one siphon is very, small. Tnstead of thermic-siphons metal tubes could be used which are only partly filled with liquid, said liquid vapor-' izing in the parts of the tube which form the grate and condensing in the upper part of said tubes which penetrates into the boiler.

In the accompanying drawings the improved grate for down-drafufurnaces is shown.

Figure l is a vertical section on line A-B of Fig. 2. Fig. 2 is a plan oi the grate (section on line Gr-l-l of Figs. 1-3). Fig. 3 is a vertical section on line CD of Fig. 2. Fig. t shows a modification of the grate.

The grate shown in Figs. 1 to 3 is composed of sixhollow grate bars coupled in pairs so as to form three separate thermiosiphons. The two bars a, a of the grate united by the bend a. (Fig. 2) form one thermic-siphon a (Figs. 1, 2, 3). Said hollow grate bars a a project horizontally from the furnace and go up in a large curve to mount vertically into the water of the boiler 12 (Figs. 1, 3). In this boiler b the vertical extensions of the hollow grate bars a a are united by the bend a The two hollow grate bars a a with their extensions and bends a a form an elongated hollow endless buckle. The endless tube is filled with mercury or with any other suitable liquid and forms a thermic-siphon. The tube could further befilled only partly with the liquid which in this case would vaporize in the part of the tube in the furnace to condense in the part situated in the boiler.

In order to favorize the condensation of! the steam and the circulation of the condensed liquid there could be used a device like that shown in Figs. 1 to 3 consisting of a tube 0,, 0 connecting the two ends of a double tube a.

The boiler b can either be an independent boiler or it can simply serve as water tank for a boiler; it could be filled with any liquid which is to be heated but not to be vaporized. i

As can be seen from the drawings the grate is used for a downdraft-furnace, the air traversing the fuel in vertical direction from above and the gases of combustion and the molten ashes escaping in the direction indicated by the arrow. With this arrangement an absolute combustion of the smoke is obtained with the minimum amount of annular, rectangular and so on. i The bars of the grate can be horizontal, inclined or curvediaccording to any suitable profile.

-As shown in Fig. 4: more than two bars of the grate could be coupled to form a thermic siphon. The grate bars can be covered with a thin layer of refractory earth in order to facilitate the escape of the molten ashes. The distance between the grate bars can be increased it between the grate and the 'fuel bricks or large pieces of refractory material are-arranged so that the intervals between same are sufliciently large to permit of the passage of the gases and of the molten ashes but not large enough to let pass the coals.

I claim:

In combination, a down draft furnace having a grate comprising a series of independent hollow tubes spaced apart, said tubes being endless and formed with a horizontal part forming the grate and a Vertical part, passing within a boiler, said boiler having a fluid to be heated therein and an auxiliary fluid circulating within the h0llow tubes for transmitting heat from the furnace to the boiler.

In witness whereof I have hereunto set my hand in the presence of two witnesses. EMILE MASLIN.

Witnesses:

MARcEn DE CAMroN, PIERRE SAUVAIRE. 

